Public support for the air war in Yugoslavia is softening and a majority of Americans believe the United States and its NATO allies should negotiate a settlement with Yugoslav President Slobodan Milosevic to end the fighting, according to a new Washington Post-ABC News poll.

But the country remains divided over exactly what concessions the United States should grant Milosevic in exchange for peace in the Balkans. Half the public agrees that NATO should not stop the bombing until the Serbs allow a NATO-led peacekeeping force into Kosovo – but nearly as many say this NATO peace requirement should be open to negotiation.

In other ways, the latest Post-ABC News poll suggests that the war for public opinion on Kosovo has entered a new, complicated and more risky phase for President Clinton and the NATO allies.

Only about half the country says NATO should continue to bomb Yugoslavia. Nearly as many say the United States and its allies should suspend the air attacks as a way to encourage Serbian forces to leave Kosovo – an option that has been repeatedly and forcefully rejected by Clinton and NATO commanders.

Since the bombing of the Chinese embassy and air strikes that have killed civilians, the proportion of Americans who say the allies are "not being careful enough to avoid civilian casualties" has increased from 19 percent to 32 percent.

The poll also found that in public perception of his handling of the Kosovo crisis, Clinton has suffered somewhat in recent weeks. Barely half of those those interviewed – 53 percent – say they approve of the way he is handling the situation in Kosovo, down from 56 percent three weeks ago and 60 percent during the first week in April. The proportion of Americans opposed to Clinton's management of the crisis has increased from 36 percent to 41 percent in three weeks.

A total of 761 randomly selected Americans were interviewed Sunday for this Post-ABC News poll. Margin of sampling error for the overall results is plus or minus 4 percentage points.

The survey suggests that war fatigue has set in after seven weeks of bombing strikes by the United States and its western allies. While the erosion in support remains modest and perhaps only temporary, it signals the first significant decline in public support for military action in Yugoslavia since the crisis began.

American support for the war, however, remains strong compared to that of several key NATO members. In Germany, polls show the public has turned against the war effort and in Italy, Prime Minister Massimo D'Alema is under increasing political pressure to work for a political solution to the Kosovo crisis.

The percentage of Americans who back the air campaign has dropped from 65 percent in late April to 59 percent in the latest survey. Opposition grew from 30 percent to 38 percent during the same period.

Fifty-eight percent of those surveyed say NATO should negotiate with Serbia on terms to end the conflict, while 38 percent say the allies should require Serbia to accept existing NATO requirements for peace – a view expressed by equally large proportions of Republicans, Democrats and independents.

Six in 10 say Milosevic should be required to remove most of his troops from Kosovo – a key NATO peace condition – while nearly four in 10 said troop withdrawals should be up for negotiation. Fifty-four percent say the return of all refugees to Kosovo should not be open to negotiations, while 42 percent say it should. But 55 percent say a settlement allowing Kosovo limited self-rule should not be a requirement for peace.

The survey revealed that the American public is backing away from sending combat troops into Kosovo. Barely half of those interviewed – 52 percent – say they favor sending in soldiers if the air campaign fails to produce peace, down from 56 percent in a Post-ABC News poll conducted three weeks ago.

At the same time, the proportion who oppose the use of ground troops increased from 40 percent to 46 percent, with most of the jump in opposition coming from independents. Among these voters, opposition to bombing increased by more than 10 percentage points.

For the first time in Post-ABC News surveys, a clear majority of Americans – 56 percent – say they would oppose sending ground troops into Kosovo if it meant that the United States would suffer "some" casualties.

Clinton has acknowledged that Americans may be growing frustrated with the length of the bombing campaign and NATO's inability to bring Milosevic to the peace table. In a speech last week, Clinton urged the country "not to forget the real victims of this tragedy" and to "pay the price of time" – even as some of his advisers fear that time may be running out.

The latest Post – ABC News poll suggests that Clinton's recent humanitarian pleas have not won him additional support for his actions in Serbia. The United States has done "the right thing" getting involved in Kosovo, according to 54 percent of those interviewed, unchanged from a survey in late April.

What has increased in recent polls is the sense that neither side is winning in Kosovo. Fewer than half of those interviewed – 45 percent – believe the U.S. and its allies are achieving victory, while 22 percent said Serbia is winning. But the proportion who say neither side is winning now stands at 28 percent, up seven percentage points since April.